| Parameter |
Value |
| Designation |
C/2003 H1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-02-22T14:57:51.929280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:29Z |
| Obs used |
1890 |
| NEO |
- |
| M1 |
11.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-08-30.0000000 |
| e |
0.99915679 |
| q (au) |
2.239626 |
| a (au) |
2656.070310 |
| i (deg) |
138.667213 |
| Ω (om, deg) |
19.000486 |
| ω (w, deg) |
196.139594 |
| M (ma, deg) |
359.998728 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.871 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.871 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.730 |
| k |
0.800 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2003-04-24 |
2004-02-21 |
+3.5205 |
-2.057 |
| 2004-02-23 |
2005-02-07 |
+17.2256 |
-6.015 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
01:52:54.13 |
+04:26:10.7 |
HIP 8765 |
13.70 |
| 2026-06-01 12:00 |
01:52:55.95 |
+04:26:19.0 |
HIP 8765 |
13.63 |
| 2026-06-02 00:00 |
01:52:57.76 |
+04:26:27.2 |
HIP 8765 |
13.57 |
| 2026-06-02 12:00 |
01:52:59.56 |
+04:26:35.3 |
HIP 8765 |
13.53 |
| 2026-06-03 00:00 |
01:53:01.34 |
+04:26:43.3 |
HIP 8765 |
13.50 |
| 2026-06-03 12:00 |
01:53:03.11 |
+04:26:51.2 |
HIP 8765 |
13.50 |
| 2026-06-04 00:00 |
01:53:04.87 |
+04:26:58.9 |
HIP 8765 |
13.51 |
| 2026-06-04 12:00 |
01:53:06.61 |
+04:27:06.6 |
HIP 8765 |
13.53 |
| 2026-06-05 00:00 |
01:53:08.34 |
+04:27:14.1 |
HIP 8765 |
13.57 |
| 2026-06-05 12:00 |
01:53:10.05 |
+04:27:21.6 |
HIP 8765 |
13.63 |
| 2026-06-06 00:00 |
01:53:11.75 |
+04:27:28.9 |
HIP 8765 |
13.70 |
| 2026-06-06 12:00 |
01:53:13.43 |
+04:27:36.1 |
HIP 8765 |
13.78 |
| 2026-06-07 00:00 |
01:53:15.10 |
+04:27:43.2 |
HIP 8765 |
13.88 |
| 2026-06-07 12:00 |
01:53:16.75 |
+04:27:50.2 |
HIP 8765 |
13.98 |
| 2026-06-08 00:00 |
01:53:18.39 |
+04:27:57.0 |
HIP 8765 |
14.10 |
| 2026-06-08 12:00 |
01:53:20.01 |
+04:28:03.8 |
HIP 8765 |
14.24 |
| 2026-06-09 00:00 |
01:53:21.62 |
+04:28:10.4 |
HIP 8765 |
14.38 |
| 2026-06-09 12:00 |
01:53:23.21 |
+04:28:16.9 |
HIP 8765 |
14.53 |
| 2026-06-10 00:00 |
01:53:24.79 |
+04:28:23.3 |
HIP 8765 |
14.69 |
| 2026-06-10 12:00 |
01:53:26.35 |
+04:28:29.6 |
HIP 8765 |
14.86 |
| 2026-06-11 00:00 |
01:53:27.90 |
+04:28:35.8 |
HIP 8765 |
15.04 |
| 2026-06-11 12:00 |
01:53:29.42 |
+04:28:41.9 |
HIP 8765 |
15.22 |
| 2026-06-12 00:00 |
01:53:30.94 |
+04:28:47.8 |
HIP 8765 |
15.41 |
| 2026-06-12 12:00 |
01:53:32.43 |
+04:28:53.6 |
HIP 8765 |
15.61 |
| 2026-06-13 00:00 |
01:53:33.91 |
+04:28:59.3 |
HIP 8765 |
15.81 |
| 2026-06-13 12:00 |
01:53:35.38 |
+04:29:04.9 |
HIP 8765 |
16.01 |
| 2026-06-14 00:00 |
01:53:36.83 |
+04:29:10.3 |
HIP 8765 |
16.22 |
| 2026-06-14 12:00 |
01:53:38.26 |
+04:29:15.7 |
HIP 8765 |
16.44 |
| 2026-06-15 00:00 |
01:53:39.67 |
+04:29:20.9 |
HIP 8765 |
16.66 |
| 2026-06-15 12:00 |
01:53:41.07 |
+04:29:26.0 |
HIP 8765 |
16.88 |
| 2026-06-16 00:00 |
01:53:42.45 |
+04:29:31.0 |
HIP 8765 |
17.10 |
| 2026-06-16 12:00 |
01:53:43.81 |
+04:29:35.8 |
HIP 8765 |
17.32 |
| 2026-06-17 00:00 |
01:53:45.15 |
+04:29:40.5 |
HIP 8765 |
17.55 |
| 2026-06-17 12:00 |
01:53:46.48 |
+04:29:45.1 |
HIP 8765 |
17.78 |
| 2026-06-18 00:00 |
01:53:47.79 |
+04:29:49.6 |
HIP 8765 |
18.01 |
| 2026-06-18 12:00 |
01:53:49.08 |
+04:29:54.0 |
HIP 8765 |
18.24 |
| 2026-06-19 00:00 |
01:53:50.36 |
+04:29:58.2 |
HIP 8765 |
18.47 |
| 2026-06-19 12:00 |
01:53:51.61 |
+04:30:02.3 |
HIP 8765 |
18.70 |
| 2026-06-20 00:00 |
01:53:52.85 |
+04:30:06.3 |
HIP 8765 |
18.93 |
| 2026-06-20 12:00 |
01:53:54.07 |
+04:30:10.2 |
HIP 8765 |
19.16 |
| 2026-06-21 00:00 |
01:53:55.27 |
+04:30:13.9 |
HIP 8765 |
19.39 |
| 2026-06-21 12:00 |
01:53:56.46 |
+04:30:17.5 |
HIP 8765 |
19.61 |
| 2026-06-22 00:00 |
01:53:57.62 |
+04:30:21.0 |
HIP 8765 |
19.84 |